Fix mash chrome crashing when hovering over link.

components/mus/ws/platform_display.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/ws/platform_display.h"
 
 #include "base/numerics/safe_conversions.h"
 #include "build/build_config.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
@@ skipping 96 matching lines @@
   if (draw_default_surface) {
     gfx::Transform quad_to_target_transform;
     quad_to_target_transform.Translate(absolute_bounds.x(),
                                        absolute_bounds.y());
 
     cc::SharedQuadState* sqs = pass->CreateAndAppendSharedQuadState();
 
     const gfx::Rect bounds_at_origin(window->bounds().size());
     // TODO(fsamuel): These clipping and visible rects are incorrect. They need
     // to be populated from CompositorFrame structs.
-    sqs->SetAll(
-        quad_to_target_transform, bounds_at_origin.size() /* layer_bounds */,
-        bounds_at_origin /* visible_layer_bounds */,
-        bounds_at_origin /* clip_rect */, false /* is_clipped */,
-        window->opacity(), SkXfermode::kSrc_Mode, 0 /* sorting-context_id */);

[sky, 2016/04/25 16:00:15]

AHA! This must be the random CHECK I randomly see:

#0 0x7f320e07e66e base::debug::StackTrace::StackTrace()
#1 0x7f320e0def5f logging::LogMessage::~LogMessage()
#2 0x7f320226efef cc::(anonymous namespace)::BlendModeFromSkXfermode()
#3 0x7f3202267c75 cc::GLRenderer::DrawRenderPassQuad()
#4 0x7f32022654f5 cc::GLRenderer::DoDrawQuad()
#5 0x7f3202251935 cc::DirectRenderer::DrawRenderPass()
#6 0x7f32022506e3 cc::DirectRenderer::DrawRenderPassAndExecuteCopyRequests()
#7 0x7f320225058e cc::DirectRenderer::DrawFrame()
#8 0x7f32010b5579 cc::Display::DrawAndSwap()
#9 0x7f32010c9d72 cc::DisplayScheduler::DrawAndSwap()
#10 0x7f32010c94a2 cc::DisplayScheduler::AttemptDrawAndSwap()
#11 0x7f32010c8eec cc::DisplayScheduler::OnBeginFrameDeadline()
#12 0x7f32010cdeb9
_ZN4base8internal15RunnableAdapterIMN2cc16DisplaySchedulerEFvvEE3RunIJEEEvPS3_DpOT_
#13 0x7f32010cddc0
_ZN4base8internal12InvokeHelperILb1EvNS0_15RunnableAdapterIMN2cc16DisplaySchedulerEFvvEEEE8MakeItSoINS_7WeakPtrIS4_EEJEEEvS7_T_DpOT0_
#14 0x7f32010cdd6d
_ZN4base8internal7InvokerINS_13IndexSequenceIJLm0EEEENS0_9BindStateINS0_15RunnableAdapterIMN2cc16DisplaySchedulerEFvvEEEFvPS7_EJNS_7WeakPtrIS7_E\

Nice!

+    sqs->SetAll(quad_to_target_transform,
+                bounds_at_origin.size() /* layer_bounds */,
+                bounds_at_origin /* visible_layer_bounds */,
+                bounds_at_origin /* clip_rect */, false /* is_clipped */,
+                window->opacity(), SkXfermode::kSrcOver_Mode,
+                0 /* sorting-context_id */);
     auto quad = pass->CreateAndAppendDrawQuad<cc::SurfaceDrawQuad>();
     quad->SetAll(sqs, bounds_at_origin /* rect */,
                  gfx::Rect() /* opaque_rect */,
                  bounds_at_origin /* visible_rect */, true /* needs_blending*/,
                  default_surface->id());
   }
   if (underlay_surface) {
     const gfx::Rect underlay_absolute_bounds =
         absolute_bounds - window->underlay_offset();
     gfx::Transform quad_to_target_transform;
     quad_to_target_transform.Translate(underlay_absolute_bounds.x(),
                                        underlay_absolute_bounds.y());
     cc::SharedQuadState* sqs = pass->CreateAndAppendSharedQuadState();
     const gfx::Rect bounds_at_origin(
         underlay_surface->last_submitted_frame_size());
     sqs->SetAll(
         quad_to_target_transform, bounds_at_origin.size() /* layer_bounds */,
         bounds_at_origin /* visible_layer_bounds */,
         bounds_at_origin /* clip_rect */, false /* is_clipped */,
         window->opacity(), SkXfermode::kSrc_Mode, 0 /* sorting-context_id */);

[sky, 2016/04/25 16:04:17]

Should this be updated too?

[kylechar, 2016/04/25 16:39:53]

It seems like this would cause a crash in the same way if opacity wasn't 1.0f.
I'll update it as well.

 
     auto quad = pass->CreateAndAppendDrawQuad<cc::SurfaceDrawQuad>();
     quad->SetAll(sqs, bounds_at_origin /* rect */,
                  gfx::Rect() /* opaque_rect */,
                  bounds_at_origin /* visible_rect */, true /* needs_blending*/,
                  underlay_surface->id());
   }
 }
 
 }  // namespace
@@ skipping 280 matching lines @@
 
 void DefaultPlatformDisplay::RequestCopyOfOutput(
     std::unique_ptr<cc::CopyOutputRequest> output_request) {
   if (top_level_display_client_)
     top_level_display_client_->RequestCopyOfOutput(std::move(output_request));
 }
 
 }  // namespace ws
 
 }  // namespace mus